Acquisition Of Nosocomial Infections Research Articles

Dynamics of nosocomial SARS-CoV-2 transmissions: Facing the challenge of variants of concern in a Brazilian reference hospital.

The hospital environment can be considered a high risk for the occurrence of SARS-CoV-2 transmission outbreaks, either for health professionals who are directly involved in the care of suspected or confirmed cases of the disease, or for patients, for being in an environment more vulnerable to the acquisition of nosocomial infections. In this molecular epidemiology study, we aimed to analyze the occurrence and transmission dynamics of SARS-CoV-2 in outbreaks and local chains of transmission in a large tertiary teaching hospital in southern Brazil, in addition to verifying circulating strains and their epidemiological relation in the local context, from September 21, 2020 to October 5, 2021. Positive samples involved in COVID-19 clusters or outbreaks were analyzed using clinical, epidemiological and genomic data. Different lineages and sublineages among patients in the same room were observed. Most patients had their first clinical manifestation, evidence of suspicion, and diagnostic confirmation within 7-14 days or >14 days after hospital admission. The patients who have contact with confirmed cases of COVID-19 spent, on average, 6.28 days in the same environment until the positive test. There was a significant association between the outcome and the number of vaccine doses (p < 0.05), where those who received two doses presented a lower occurrence of death. There was a total replacement of variant of concern (VOC) Gamma by VOC Delta from August 2021 at the study site. Although the epidemiological analysis indicates nosocomial infections, through genomic sequencing, it was established that most of the hospital outbreaks had different origins. These findings highlight the utility of integrating epidemiological and genomic data to identify possible routes of viral entry and dissemination.

Impact of Inflammatory Response Modifiers on the Incidence of Hospital-Acquired Infections in Patients with COVID-19.

IntroductionThe study aim was to assess the influence of inflammatory response modifiers, including anti-interleukin-6 (IL-6) biologics and corticosteroids, on the incidence of hospital-acquired infections in patients with coronavirus disease 2019 (COVID-19).MethodsCase–control study performed at a university hospital from February 26 to May 26, 2020. Cases were defined as patients with COVID-19 who developed hospital-acquired infections. For each case, two controls were selected among patients without infections. Cases and controls were matched obeying three criteria in a hierarchical sequence: length of hospital stay up until the first infection; comorbidity; and need for Intensive care unit (ICU) admission. Conditional logistic regression analysis was used to estimate the association of exposures with being a case.ResultsA total of 71 cases and 142 controls were included. Independent predictors for acquiring a hospital infection were chronic liver disease [odds ratio (OR) 16.56, 95% CI 1.87–146.5, p = 0.012], morbid obesity (OR 6.11, 95% CI 1.06–35.4, p = 0.043), current or past smoking (OR 4.15, 95% CI 1.45–11.88, p = 0.008), exposure to hydroxychloroquine (OR 0.2, 95% CI 0.041–1, p = 0.053), and invasive mechanical ventilation (OR 61.5, 95% CI 11.08–341, p ≤ 0.0001).ConclusionsInflammatory response modifiers had no influence on acquisition of nosocomial infections in admitted patients with COVID-19. Hospital-acquired infections primarily occurred in the critically ill and invasive mechanical ventilation was the main exposure conferring risk.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40121-021-00477-9.

A Study of Nosocomial Infections in Intensive Care Units of Local Tertiary Care Hospitals

Introduction: It has been reported that the incidence of nosocomial infections in the intensive care unit (ICU) is about 2–5 times higher than in the general in-patient hospital population. The objectives of the present study were to determine the incidence of nosocomial infection, to identify possible risk factors for these infections, to clarify the distribution of the causative pathogens, and to evaluate the outcome of the infected patients in terms of length of ICU and hospital stay and mortality. Methods: This was a retrospective and analytical study. For classification of the different causative pathogens associated with nosocomial infections, all the microorganisms isolated on culture from each of the patients with confirmed infection according to the Centers for Disease Control and Prevention definitions were recorded and their relative frequency of isolation was determined as percentage. Bacterial isolates were identified by Gram stain, cultures on routine media and where necessary, selective media, and specific biochemical tests following standard protocols. Results: Nosocomial infections were in 28 patients. The most frequently diagnosed nosocomial infection was nosocomial pneumonia. A total of 39 pathogens were isolated on culture and accounted for the nosocomial infections in 28 patients. Some infections were polymicrobial. Gram-negative Enterobacteriaceae were the most frequently isolated pathogens. There was no statistically significant difference between the hospital mortality rates among the patients with and without nosocomial infection. Conclusion: Gram-negative Enterobacteriaceae, as a group, were the most frequently isolated pathogens, while Pseudomonas aeruginosa was the single most frequent causative organism. The acquisition of nosocomial infections in the ICU resulted in significantly increased length of ICU and hospital stay, but did not result in statistically significant increase in ICU or hospital mortality. These findings can now be utilized toward planning a surveillance program for nosocomial infection in our ICU setting as a first step toward a better infection control strategy.

SARS-CoV-2-Induced ARDS Associates with MDSC Expansion, Lymphocyte Dysfunction, and Arginine Shortage.

PurposeThe SARS-CoV-2 infection can lead to a severe acute respiratory distress syndrome (ARDS) with prolonged mechanical ventilation and high mortality rate. Interestingly, COVID-19-associated ARDS share biological and clinical features with sepsis-associated immunosuppression since lymphopenia and acquired infections associated with late mortality are frequently encountered. Mechanisms responsible for COVID-19-associated lymphopenia need to be explored since they could be responsible for delayed virus clearance and increased mortality rate among intensive care unit (ICU) patients.MethodsA series of 26 clinically annotated COVID-19 patients were analyzed by thorough phenotypic and functional investigations at days 0, 4, and 7 after ICU admission.ResultsWe revealed that, in the absence of any difference in demographic parameters nor medical history between the two groups, ARDS patients presented with an increased number of myeloid-derived suppressor cells (MDSC) and a decreased number of CD8pos effector memory cell compared to patients hospitalized for COVID-19 moderate pneumonia. Interestingly, COVID-19-related MDSC expansion was directly correlated to lymphopenia and enhanced arginase activity. Lastly, T cell proliferative capacity in vitro was significantly reduced among COVID-19 patients and could be restored through arginine supplementation.ConclusionsThe present study reports a critical role for MDSC in COVID-19-associated ARDS. Our findings open the possibility of arginine supplementation as an adjuvant therapy for these ICU patients, aiming to reduce immunosuppression and help virus clearance, thereby decreasing the duration of mechanical ventilation, nosocomial infection acquisition, and mortality.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10875-020-00920-5.

The relationship between immune status as measured by stimulated ex-vivo tumour necrosis factor alpha levels and the acquisition of nosocomial infections in critically ill mechanically ventilated patients

IntroductionImmunological dysfunction is common in critically ill patients but its clinical significance and the optimal method to measure it are unknown. The level of tumor necrosis factor alpha (TNF-α) after ex-vivo whole blood stimulation with lipopolysaccharide (LPS) has been proposed as a possible method to quantify immunological function. We hypothesized that in a cohort of critically ill patients, those with a lower post-stimulation TNF-α level would have increased rates of nosocomial infections (NIs) and worse clinical outcomes.MethodsA secondary analysis of a phase 2 randomized, multi-centre, double-blinded placebo-controlled trial. As there was no difference between treatment and control arms in outcomes and NI rate, all the patients were analyzed as one cohort. On enrolment, day 4, 7, and weekly until day 28, whole blood was incubated with LPS ex-vivo and subsequent TNF-α level was measured. Patients were grouped in tertiles according to delta and peak TNF-α level. The primary outcome was the association between NIs and tertiles of TNF-α level post LPS stimulation; secondary outcomes included ICU and 90-day mortality, and ICU and hospital length of stay.ResultsData was available for 201 patients. Neither the post LPS stimulation delta TNF-α group nor the peak TNF-α post-stimulation group were associated with the development of NIs or clinical outcomes. Patients in the highest tertile for post LPS stimulation delta TNF-α compared to the lowest tertile were younger [61.1 years ± 15.7 vs. 68.6 years ± 12.8 standard deviations (SD) in the lowest tertile], had lower acuity of illness (APACHE II 25.0 ± 9.7 vs. 26.7 ± 6.1) and had lower baseline TNF-α (9.9 pg/mL ± 19.0 vs. 31.0 pg/mL ± 68.5). When grouped according to peak post-stimulation TNF-α levels, patients in the highest tertile had higher serum TNF-α at baseline (21.3 pg/mL ± 66.7 compared to 6.5 pg/mL ± 9.0 in the lowest tertile).ConclusionIn this prospective multicenter study, ex-vivo stimulated TNF-α level was not associated with the occurrence of NIs or clinical outcomes. Further study is required to better ascertain whether TNF levels and ex-vivo stimulation can be used to characterize immune function in critical illness and if other assays might be better suited to this task.

Multidrug-resistant Acinetobacter baumannii outbreaks: a global problem in healthcare settings.

INTRODUCTION: The increase in the prevalence of multidrug-resistant Acinetobacter baumannii infections in hospital settings has rapidly emerged worldwide as a serious health problem. METHODS: This review synthetizes the epidemiology of multidrug-resistant A. baumannii, highlighting resistance mechanisms. CONCLUSIONS: Understanding the genetic mechanisms of resistance as well as the associated risk factors is critical to develop and implement adequate measures to control and prevent acquisition of nosocomial infections, especially in an intensive care unit setting.

Bloodstream infections in the elderly: what is the real goal?

Bloodstream infections (BSI) represent a serious bacterial infection with substantial morbidity and mortality. Population-based studies demonstrate an increased incidence, especially among elderly patients. Controversy exists regarding whether presentation of BSI are different in older patients compared to younger patients; our narrative review of the literature suggests that BSI in elderly patients would probably include one or more of the traditional symptoms/signs of fever, severe sepsis or septic shock, acute kidney injury, and/or leukocytosis. Sources of BSI in older adults are most commonly the urinary tract (more so than in younger adults) and the respiratory tract. Gram-negative bacteria are the most common isolates in the old (~ 40-60% of BSI); isolates from the elderly patient population show higher antibiotic resistance rates, with long-term care facilities serving as reservoirs for multidrug-resistant bacteria. BSI entail significantly higher rates of mortality in older age, both short and long term. Some of the risk factors for mortality are modifiable, such as the appropriateness of empirical antibiotic therapy and nosocomial acquisition of infection. Health-related quality of life issues regarding the elderly patient with BSI are not well addressed in the literature. Utilization of comprehensive geriatric assessment and comprehensive geriatric discharge planning need to be investigated further in this setting and might serve as key for improved results in this population. In this review, we address all these aspects of BSI in old patients with emphasis on future goals for management and research.

The prevalence of antiseptic tolerance genes among staphylococci and enterococci in a pediatric population.

The smr and qacA/B genes in Staphylococcus aureus confer tolerance to antiseptics and are associated with nosocomial acquisition of infection and underlying medical conditions. Such antiseptic tolerance (AT) genes have also been reported in coagulase-negative staphylococci (CoNS) and enterococci, however, few data are available regarding their prevalence. We sought to describe the frequency of AT genes among bloodstream isolates of S. aureus, CoNS and enterococci at Texas Children's Hospital (TCH). Banked CoNS, S. aureus and enterococci isolated from blood cultures collected bewteen October 1, 2016, and October 1, 2017, were obtained from the TCH clinical microbiology laboratory. All isolates underwent polymerase chain reaction (PCR) assay for the qacA/B and smr genes. Medical records were reviewed for all cases. In total, 103 CoNS, 19 Enterococcus spp, and 119 S. aureus isolates were included in the study, and 80.6% of the CoNS possessed at least 1 AT gene compared to 37% of S. aureus and 43.8% of E. faecalis isolates (P &lt; .001). Among CoNS bloodstream isolates, the presence of either AT gene was strongly associated with nosocomial infection (P &lt; .001). The AT genes in S. aureus were associated with nosocomial infection (P = .025) as well as the diagnosis of central-line-associated bloodstream infection (CLABSI; P = .04) and recent hospitalizations (P &lt; .001). We found no correlation with genotypic AT in E. faecalis and any clinical variable we examined. Antiseptic tolerance is common among bloodstream staphylococci and E. faecalis isolates at TCH. Among CoNS, the presence of AT genes is strongly correlated with nosocomial acquisition of infection, consistent with previous studies in S. aureus. These data suggest that the healthcare environment contributes to AT among staphylococci.

A high mortality rate associated with multidrug-resistant Acinetobacter baumannii ST79 and ST25 carrying OXA-23 in a Brazilian intensive care unit.

The global spread of carbapenem-resistant Acinetobacter baumannii (A. baumannii) strains has restricted the therapeutic options available to treat infections due to this pathogen. Understanding the prevalence of such infections and the underlying genetic mechanisms of resistance may help in the implementation of adequate measures to control and prevent acquisition of nosocomial infections, especially in an intensive care unit setting. This study describes the molecular characteristics and risk factors associated with OXA-23-producing A. baumannii infections. A case-control study was undertaken from September/2013 to April/2015. Acquisition of OXA-23-producing A. baumannii was found to be associated with the use of nasogastric tubes, haemodialysis, and the use of cephalosporins. These isolates were only susceptible to amikacin, gentamicin, tigecycline, and colistin, and contained the ISAba1 insertion sequence upstream ofblaOXA-23 and blaOXA-51 genes. Twenty-six OXA-23-producing A. baumannii strains belonged to the ST79 (CC79) clonal group,and patients infected or colonised by these isolates had a higher mortality rate (34.6%). In conclusion, this study showed a dissemination of OXA-23-producing A. baumannii strains that was associated with several healthcare-related risk factors and high mortality rates among intensive care unit patients.

2308. The Prevalence of Antiseptic Tolerance Genes Among Gram-Positive Bloodstream Pathogens in Children

BackgroundThe presence of the smr and qacA/B genes in Staphylococcus aureus have been correlated with reduced susceptibility to antiseptics. Recently, S. aureus bearing these genes have been reported to be associated with nosocomial acquisition of infection and underlying medical conditions. Antiseptic tolerance (AT) genes have also been reported in coagulase negative staphylococci (CoNS) and enterococci; however, little data are available regarding their prevalence. We sought to describe the frequency of smr and qacA/B among bloodstream isolates of S. aureus, CoNS and enterococci obtained at Texas Children’s Hospital (TCH).MethodsBanked CoNS, S. aureus and enterococci isolated from blood cultures collected from October 1, 2016 to October 1, 2017 were obtained from the TCH clinical microbiology laboratory. All isolates underwent PCR for the qacA/B and smr genes. CoNS and enterococci were identified to the species level with MALDI-TOF mass spectrometry. Medical records were reviewed for all cases; CoNS were considered true pathogens if >1 blood culture was positive.Results268 CoNS, 19 Enterococcus spp. and 116 S. aureus isolates were identified and included (Figure 1). 83.2% of CoNS possessed at least one AT gene compared with 36.2% of S. aureus and 31.5% of enterococci (P < 0.001, Figure 2). Neither antiseptic gene was detected in E. faecium isolates (n = 4) compared with 43.8% of E. faecalis (P = 0.2). Among CoNS, methicillin-resistance was found more commonly among qacA/B-positive (77.2% vs. 40%, P = 0.04) and smr-positive isolates (93.8% vs. 60.5%, P = 0.02). 38.4% of CoNS bloodstream isolates were considered true infections; among these, the presence of either AT gene was strongly associated with nosocomial infection (P < 0.001). AT genes in S. aureus were associated with nosocomial infection (P = 0.007) as well as the diagnosis of CLA-BSI (P = 0.001). There was no correlation with genotypic AT in enterococci and any examined clinical variable.ConclusionAT is common among bloodstream staphylococci and E. faecalis isolates at TCH. Among CoNS, the presence of AT genes is strongly correlated with nosocomial acquisition of infection consistent with previous studies in S. aureus. These data suggest that the healthcare environment contributes to AT among staphylococci. Disclosures All authors: No reported disclosures.

Tuberculosis Recommendations for Solid Organ Transplant Recipients and Donors.

Tuberculosis Recommendations for Solid Organ Transplant Recipients and Donors.

Antipyretic Therapy in Critically Ill Septic Patients: A Systematic Review and Meta-Analysis.

This meta-analysis aimed to examine the impact of antipyretic therapy on mortality in critically ill septic adults. Literature searches were implemented in Ovid Medline, Embase, Scopus, Cumulative Index of Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, and ClinicalTrials.gov through February 2016. Inclusion criteria were observational or randomized studies of septic patients, evaluation of antipyretic treatment, mortality reported, and English-language version available. Studies were excluded if they enrolled pediatric patients, patients with neurologic injury, or healthy volunteers. Criteria were applied by two independent reviewers. Two reviewers independently extracted data and evaluated methodologic quality. Outcomes included mortality, frequency of shock reversal, acquisition of nosocomial infections, and changes in body temperature, heart rate, and minute ventilation. Randomized and observational studies were analyzed separately. Eight randomized studies (1,507 patients) and eight observational studies (17,432 patients) were analyzed. Antipyretic therapy did not reduce 28-day/hospital mortality in the randomized studies (relative risk, 0.93; 95% CI, 0.77-1.13; I = 0.0%) or observational studies (odds ratio, 0.90; 95% CI, 0.54-1.51; I = 76.1%). Shock reversal (relative risk, 1.13; 95% CI, 0.68-1.90; I = 51.6%) and acquisition of nosocomial infections (relative risk, 1.13; 95% CI, 0.61-2.09; I = 61.0%) were also unchanged. Antipyretic therapy decreased body temperature (mean difference, -0.38°C; 95% CI, -0.63 to -0.13; I = 84.0%), but not heart rate or minute ventilation. Antipyretic treatment does not significantly improve 28-day/hospital mortality in adult patients with sepsis.

Epidemiology and characteristics of nosocomial infections in critically ill patients in a tertiary care Intensive Care Unit of Northern India.

Background and Aims:The prevalence of nosocomial infection is higher in the Intensive Care Unit (ICU) than other areas of the hospital. The present observational study was undertaken to describe the epidemiology and characteristics of nosocomial infections acquired in a tertiary care ICU and the impact of the various risk factors in their causation.Materials and Methods:A retrospective study was conducted on the prospectively collected data of 153 consecutive patients admitted in a tertiary care ICU between July 2014 and December 2015. The primary objective was to assess the epidemiology of ICU-acquired bacterial infections in terms of the incidence of new infections, causative organism, and site. The secondary end point was to assess the risk factors for developing ICU-acquired infections.Results:Out of the 153 patients enrolled in the study, 87 had an ICU-acquired nosocomial infection (58.86%). The most common organism responsible for infection was Klebsiella pneumoniae (37%), and the most common infection was pneumonia (33%). The duration of mechanical ventilation and length of ICU stay were significantly prolonged in patients developing nosocomial infections. There was no difference in mortality between the groups. The multivariate analyses identified intubation longer than 7 days, urinary catheterization >7 days, duration of mechanical ventilation more than 7 days, and ICU length of stay longer than 7 days as independent risk factors for nosocomial infections.Conclusion:The study demonstrated a high incidence of nosocomial infection in the ICU and identified the risk factors for acquisition of nosocomial infections in the ICU.

Community-based Management of Micronutrient deficiency in Malnourished Children in Ghana

The relationship between undernutrition and ill health is complex. It is complicated by growth retardation, impaired mental development, and significant morbidity from malaria, diarrhoeal diseases, pneumonia etc. and mortality. Several micronutrients are required for adequate growth and development especially in young children. They also account for three of the four most important forms of malnutrition worldwide. This review attempts to evaluate the community-based management of malnutrition in developing countries while comparing it to the in-patient management of malnourished children. Parameters evaluated include cost, coverage, choice, nosocomial infection acquisition and effect on productivity. The community-based management of severe malnutrition has many benefits that should be harnessed by healthcare givers so as to reduce the burden of malnutrition in low resource settings.DOI: http://dx.doi.org/10.3329/bjms.v13i4.20552Bangladesh Journal of Medical Science Vol.13(4) 2014 p.383-387

Continued Emergence of USA300 Methicillin-ResistantStaphylococcus aureusin the United States: Results from a Nationwide Surveillance Study

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is changing, with USA300 emerging first in community and then in healthcare settings. We performed nationwide surveillance to assess recent trends in the molecular epidemiology of MRSA. One hundred consecutive unique clinically significant S. aureus isolates were recovered from patients at each of 43 US centers between July 1, 2011, and December 31, 2011. Susceptibility testing, pulsed-field gel electrophoresis (PFGE), staphylococcal protein A gene (spa) and staphylococcal cassette chromosome mec typing, and Panton-Valentine leukocidin detection were performed on all MRSA isolates. Of 4,131 isolates collected, 2,093 (51%) were MRSA. Specimen sources of MRSA isolates included wound or abscess (54%), blood (24%), lower respiratory tract (11%), and other sterile site (10%). Thirty percent were isolated more than 48 hours after hospital admission (ie, were associated with nosocomial acquisition of infection). USA300 was the most common PFGE type (1,269 isolates; 61%), overall and in all regions, followed by USA100 (368 isolates; 18%). Among 173 spa types found, the most common were t008 (51%) and t002 (18%); no other spa type accounted for more than 2% of isolates. One strain type (USA300/t008/IV) constituted almost half of all MRSA isolates (1,005 isolates; 48%) and was the most common at all body sites, causing 37% of MRSA bloodstream infections (BSIs) and 38% of nosocomial MRSA infections. Multidrug-resistant phenotypes were found among 34 USA300 isolates (3%) from 18 states. The USA300 PFGE type continues to advance nationwide. A single strain type (USA300/t008/IV) predominates in all regions and infection sites and is now more common than USA100 as a cause of MRSA BSI and nosocomial infections. Although most USA300 retain typical susceptibility profiles, multidrug-resistant phenotypes are emerging.

Third-Generation Cephalosporin-Resistant Spontaneous Bacterial Peritonitis: A single-Centre Experience and Summary of Existing Studies

Spontaneous bacterial peritonitis (SBP) is the most prevalent bacterial infection in patients with cirrhosis. Although studies from Europe have reported significant rates of resistance to third-generation cephalosporins, there are limited SBP-specific data from centres in North America. To evaluate the prevalence of, predictors for and clinical impact of third-generation cephalosporin-resistant SBP at a Canadian tertiary care centre, and to summarize the data in the context of the existing literature. SBP patients treated with both antibiotics and albumin therapy at a Canadian tertiary care hospital between 2003 and 2011 were retrospectively identified. Multivariate logistic regression was used to determine independent predictors of third-generation cephalosporin resistance and mortality. In 192 patients, 25% of infections were nosocomial. Forty per cent (77 of 192) of infections were culture positive; of these, 19% (15 of 77) were resistant to third-generation cephalosporins. The prevalence of cephalosporin resistance was 8% with community-acquired infections, 17% with health care-associated infections and 41% with nosocomial acquisition. Nosocomial acquisition of infection was the only predictor of resistance to third-generation cephalosporins (OR 4.0 [95% CI 1.04 to 15.2]). Thirty-day mortality censored for liver transplantation was 27% (50 of 184). In the 77 culture-positive patients, resistance to third-generation cephalosporins (OR 5.3 [1.3 to 22]) and the Model for End-stage Live Disease score (OR 1.14 [1.04 to 1.24]) were independent predictors of 30-day mortality. Third-generation cephalosporin-resistant SBP is a common diagnosis and has an effect on clinical outcomes. In an attempt to reduce the mortality associated with resistance to empirical therapy, high-risk subgroups should receive broader empirical antibiotic coverage.

Combined dysfunctions of immune cells predict nosocomial infection in critically ill patients

Nosocomial infection occurs commonly in intensive care units (ICUs). Although critical illness is associated with immune activation, the prevalence of nosocomial infections suggests concomitant immune suppression. This study examined the temporal occurrence of immune dysfunction across three immune cell types, and their relationship with the development of nosocomial infection. A prospective observational cohort study was undertaken in a teaching hospital general ICU. Critically ill patients were recruited and underwent serial examination of immune status, namely percentage regulatory T-cells (Tregs), monocyte deactivation (by expression) and neutrophil dysfunction (by CD88 expression). The occurrence of nosocomial infection was determined using pre-defined, objective criteria. Ninety-six patients were recruited, of whom 95 had data available for analysis. Relative to healthy controls, percentage Tregs were elevated 6-10 days after admission, while monocyte HLA-DR and neutrophil CD88 showed broader depression across time points measured. Thirty-three patients (35%) developed nosocomial infection, and patients developing nosocomial infection showed significantly greater immune dysfunction by the measures used. Tregs and neutrophil dysfunction remained significantly predictive of infection in a Cox hazards model correcting for time effects and clinical confounders {hazard ratio (HR) 2.4 [95% confidence interval (CI) 1.1-5.4] and 6.9 (95% CI 1.6-30), respectively, P=0.001}. Cumulative immune dysfunction resulted in a progressive risk of infection, rising from no cases in patients with no dysfunction to 75% of patients with dysfunction of all three cell types (P=0.0004). Dysfunctions of T-cells, monocytes, and neutrophils predict acquisition of nosocomial infection, and combine additively to stratify risk of nosocomial infection in the critically ill.

Spontaneous gram-negative bacillary meningitis in adult patients: characteristics and outcome

BackgroundSpontaneous meningitis caused by gram-negative bacilli in adult patients is uncommon and poorly characterized. Our objective is to describe and compare the characteristics and the outcome of adult patients with spontaneous gram-negative bacilli meningitis (GNBM) and spontaneous meningitis due to other pathogens.MethodsProspective single hospital-based observational cohort study conducted between 1982 and 2006 in a university tertiary hospital in Barcelona (Spain). The Main Outcome Measure: In-hospital mortality.ResultsGram-negative bacilli meningitis was diagnosed in 40 (7%) of 544 episodes of spontaneous acute bacterial meningitis. The most common pathogens were Escherichia coli and Pseudomonas species. On admission, characteristics associated with spontaneous gram-negative bacilli meningitis by multivariate modeling were advanced age, history of cancer, nosocomial acquisition of infection, urinary tract infection as distant focus of infection, absence of rash, hypotension, and a high cerebrospinal fluid white-cell count. Nine (23%) episodes were acquired in the hospital and they were most commonly caused by Pseudomonas. The in-hospital mortality rate was 53%. The mortality rate was higher among patients with Gram-negative bacillary meningitis than among those with other bacterial meningitis and their risk of death was twenty times higher than among patients infected with Neisseria meningitidis (odds ratio 20.47; 95% confidence interval 4.03-103.93; p<0.001).ConclusionsGram-negative bacilli cause 9% of spontaneous bacterial meningitis of known etiology in adults. Characteristics associated with GNBM include advanced age, history of cancer, nosocomial acquisition, and urinary tract infection as distant focus of infection. The mortality rate is higher among patients with gram-negative bacillary meningitis than among those with other bacterial meningitides.

Emergence of Unusual Nonfermenting Gram-Negative Nosocomial Pathogens in a Saudi Hospital

This study aimed to determine the frequency of isolation and prevalence of drug resistance in nonfermenting Gram-negative bacilli (NFGNB) other than Pseudomonas aeruginosa and predisposing factors for the acquisition of nosocomial infections caused by these emerging pathogens in a Saudi tertiary care hospital. A total of 125 nonduplicating NFGNB nosocomial strains were isolated, of these, 68 (54.4%) were Acinetobacter baumannii, 26 (20.8%) Stenotrophomonas maltophilia, 14 (11.2%) Alcaligenes faecalis, 12 (9.6%) Chryseobacterium indologenes, and 5 (4%) Ralstonia pickettii. MICs of 11 antibiotics were determined using the reference broth microdilution method. With the exception of colistin that inhibited 100% of A. baumannii isolates, trimethoprim/sulfamethoxazole that inhibited 100% of S. maltophilia isolates, and carbapenems that inhibited 100% of A. faecalis isolates, none of the tested antimicrobial agents inhibited 100% of the other NFGNB spp. Our results emphasize that clinicians and microbiologists should consider A. faecalis, C. indologenes, and R. pickettii as emerging nosocomial pathogens. In addition, local resistance data are essential for helping physicians in deciding an appropriate antibiotic for empirical therapy of infections with these emerging and unusual NFGNB.

Innate Immune Dysfunction in Trauma Patients

Innate Immune Dysfunction in Trauma Patients